Diesel Data: Automotive Repair

Test K

PINPOINT TEST K: LOUD POPPING SOUND WHEN CYCLING THE IGNITION SWITCH


Test K1-K3:






Test K4-K5:






Normal Operation
The START input circuit 50-MD15 (GY/OG) is sent to the audio unit when the ignition switch is turned to the START position. The audio unit then immediately mutes all speaker amplifier outputs and the subwoofer amplifier enable circuit output to eliminate the possibility of speaker pops during engine cranking.

Possible Causes
- subwoofer amplifier
- audio unit
- circuit 7-MD19 (YE/RD) short to power